The present invention relates generally to an apparatus and method for asynchronously analyzing data to detect nuclear weapons and/or radioactive material and, more particularly, to an apparatus and method for asynchronously analyzing data to detect nuclear weapons and/or radioactive material within a vessel or container during shipment from one location to another.
There is a growing concern that terrorists or others may at some time in the near future attempt to import into the United States or some other country radioactive or nuclear material which may then be used for the construction of a nuclear weapon for carrying out terrorist objectives. One way of shipping such radioactive or nuclear material is to hide the material among or within seemingly innocuous cargo. For example, such nuclear material could be placed within a standard, sealed cargo container of the type typically employed for shipping cargo by sea, rail, air or by truck. The nuclear material could be positioned within such a sealed cargo container along with other innocuous goods with the container being positioned, for example, within the hold of a large container ship which may be transporting a thousand or more such containers from one location to another. Typically, existing cargo inspection systems are employed either at the port of debarkation or the port of entry for such container ships. Because of the large number of containers which are typically transported by a single large container ship, it is difficult, if not impossible, using the presently available inspection equipment and personnel to thoroughly check each and every container for the presence of any type of contraband, including radioactive or nuclear material. A more typical scenario presently is to provide spot-checks of a certain number of containers in a given shipment using, for example, active scanning technology such as X-ray, gamma ray or even neutron interrogation of the selected containers which is done on a small sub-set of the overall number of containers. An active scan is anytime an outside energy source is introduced to interrogate or stimulate materials within an object such as a container. Active scans may include neutrons, Gamma rays, magnetic resonance, electromagnetic waves such as infrared, radiofrequency, X-ray, conceivably even ultrasonic, and the like. Generally, active scanning systems include a neutron detector of some sort for detecting neutrons emitted from excited materials within the object or container.
Other types of scanning technologies, which are not fully commercially developed, but which may also be considered to be active scanning inspection systems include nuclear fluorescence and thermal nuclear analysis (TNA). A nuclear fluorescence system irradiates an object to be tested with a particular radiant spectrum and if there is nuclear material within the object a different energy is emitted back out from the object. For example using neutrons from a deuterium—deuterium reaction, such neutrons have sufficient energy to activate Uranium-235 or Plutonium, among others, which causes a fission reaction in that material (e.g., input 4–5 MeV and get 6+ MeV out due to the fission reaction). Detecting a higher energy output from the object is an indication that there is an “amplifier” inside the object. Thermal neutrons used in TNA have a very low velocity. If a neutron is produced in a fission reaction activated by a thermal neutron, it usually emitted at high energy nominally 2 MeV where 1 eV is equivalent to about 10 K degrees with one degree of freedom. The presense of fissionable material is revealed by detection of such a high energy emission. Presently, active scanning inspection equipment do not operate and get analyzed quickly enough to provide real-time scanning for every container. One proposed solution is to scan the containers as they are received at the port of loading and then put the containers in storage pending on-loading. The analysis time of such scanned images slows that process because it requires expertise (similar to radiology and X-ray interpretation). When the data has been analyzed, a particular container may then be flagged for a more thorough or detailed inspection which not only causes delays in the transport of the containers, as well as potential huge back ups in the loading and unloading of the container ships, but is too late in detecting the presence of nuclear material or suspected shielded containers.
Another way to analyze containers for potential threats is by analyzing manifest information or container source/destination data. A problem with detecting nuclear and fissile materials shielded in containers using only container manifest information or container source/destination data are potential transshipment diversionary tactics. Terrorists wishing to conceal the nuclear material and/or shielding may make modifications to the container or the container contents in an attempt to veil nuclear material and/or shielding. Alternatively, such terrorists may ship the containers to a number of intermediate destinations which would not be recognized as high risk sources themselves directly. Likewise, a terrorist organization may bribe, coerce, convince or dupe a shipper, such as a “less than container load” (LCL) shipper, into adding an illicit crate into a consolidated shipment. In an extreme case, a terrorist organization may acquire a company that already has an established shipping record for innocuous materials and ship an entire container loaded with nuclear material under the name of the acquired company. The likelihood of detecting such a container by spot check active scanning and limited manifest information or container source/destination data is very low.
It is desirable to have an apparatus and method for asynchronously analyzing data to detect radioactive material within a sealed container which is within a vessel while the container is in transit from one location to another. In this manner, it is possible to more accurately identify potential threats while in transit using data from multiple sources to permit appropriate action to be taken long before the radioactive or nuclear material enters the territorial limits of a country.